Odd shaped melons

[blackthumbmary]

During my melon season, I always get a few odd shaped melons. Instead of being perfectly round, they tend to be gourd shaped..as if one side did not quite fill out. They taste fine although they never seem to get quite as big or sweet as their normal shaped relatives.

It seems like the later setting fruits are more prone to this. for example, the plant will set the first batch of fruit that are normal shaped....but then the latter batches will have a few odd shaped smaller ones. As the plant winds down production, I get even more of these oddballs.

I grow them on clay soil amended with aged horse manure. I prep the melon beds with horse manure but do not side dress the plants with manure or other amendments. I water (w/ a sprinkler) deeply once a week if there has been no rain (that week). I have tried watering more...as well as prepping the beds with more manure....but I still get a few oddballs..especially as the season and plants wind down.

I get lots of normal shaped fruits that I am not overly concerned...rather just curious as to what was causing this. Maybe just weaker fruit..or the plant winding down..or is it a nutrient deficiency becoming more pronounced as the plant sets more batches of melons.

Thanks for any ideas or advice